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Given that a high amount of sedentary behavior is a global health issue, reducing
sitting time is emerging as a novel intervention strategy and a workplace health
priority. Sit-stand workstations have been introduced to the workplace, and can be
used to rotate between sitting and standing postures at work. It is important to develop
and evaluate sit-stand interventions that aim to induce behavioral changes and
potential health benefits, in order to effectively implement them into practice.
Therefore, this thesis examined whether and to what extent sit-stand workstations can
reduce occupational sitting and improve health indexes in a real workplace. The thesis
included four studies in field and laboratory settings using several methodological
approaches such as EMG and accelerometry to examine: 1) validity of self-report
occupational sitting time (n = 70); 2) intervention effectiveness (n = 45); 3) comparison
of muscle activity patterns and spinal loading (n = 24); 4) acute physiological responses
to sitting and standing (n = 18). Overall, occupational sitting represented ~80% or less
of daily work hours among office-based workers. A validation study using long-term
questionnaire and short-term daily recall showed that while at the group level both of
these self-reported measures are acceptable (< 3% difference compared to thigh-
mounted accelerometry) for assessing the proportion of work time spent sitting, they
are not necessarily reliable at an individual level due to large individual variability.
When the questionnaire was used in a 6-month intervention study, working at a sit-
stand workstation led to a ~7% reduction in occupational sitting, and improved
perceived musculoskeletal comfort and work ability in office workers. About 42% of
the participants who had a sit-stand desk used its function on a daily basis and showed
~14% reduction in sitting time. The cross-sectional comparison study showed that
office workers using sit–stand workstations had ~15% less muscle inactivity time and
~11% more light muscle activity time during one work day, but the same amount of
spinal shrinkage compared to office workers using sit workstations. In a laboratory-
based randomized crossover trial, two hours of standing as compared to seated work
increased muscle activity, energy expenditure and circulating glucose level after
glucose loading. The results highlighted fuel switching in favor of fat oxidation during
standing, in spite of extra carbohydrate availability. In conclusion, using sit-stand
workstations seems to be a promising strategy to reduce occupational sitting time and
improve health-related outcomes, although more studies are required to address the
best practices for implementing these workstations into workplace settings.
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